Officers converged on the university's Glen Garage on Cross Campus Drive near York Road, university spokeswoman Gay Pinder said, but no signs of a shooting were found.

Ten minutes after the first tweet, the university sent another: "It is believed the report is false. Resume normal activities with caution."

Baltimore County police turned the investigation over to Towson University police.

On campus Friday afternoon, some students described a fleeting moment of panic. Others were unaware of the threat.

Casey Jendras, a junior business major, said he was sitting in math class when he heard police sirens.

Jendras said that he received three texts within 10 minutes from the university. The first reported an unconfirmed shooting and the last said it was a false alarm.

The university also made an announcement on an intercom system.

"It had us a little worried," Jendras said. "But we went from panic to relief in a matter of minutes."

Thomas Kotlar, a senior physics major, said that he was in a seminar when he noticed his classmates looking at their phones. He said he began to hear whispers about a shooting and saw a professor lock the door.

He said he was confident the university would take the proper security measures.

"I thought for a few moments about what my walk over to my car would be like," Kotlar said. "But I was inside, so I felt safe."

Howard County police said Timothy Mark Fuller, the man they claim shot his sister-in-law before officials found her body inside a burning trailer in Elkridge Saturday, was arrested Sunday morning in Florida.